Detachable blade drag bit



y 1933- H. J. HAWTHORNE 1,919,553

DETACHABLE BLADE DRAG BIT Filed March 11, 1933 2 Sheets-Sheet 1 HM 5513' Z%@M y 25, 1933-' H. J. HAWTHORNE 1,919,553

DETACHABLE BLADE DRAG BIT Filed March 11, 1933 2 Sheets-Sheet 2 Patented July 25, 1933 ulv 'ral) STATES PAT HERBERT J. HAw THoRNnoF counon, TEXAS .DETAGI-IABLE BLADE DRAG BIT Application'filed March '11, 1933. Serial No. 660,411. 7 I

My invention relates to well drills for use in drilling deep wells for oil, gas, sulphur and the like, and pertains'more particularly to bits of the scraping typein which the material at the bottom'of the hole is removed through a scraping or cutting blade.

It is an object of the inventionto provide a bit having a detachable blade thereon which may be mounted or removed from the" head of the bit conveniently and exped tiously.

It is another object to provide a bit head having a detachabieblade thereon, and inwhich the flushing fluid may be I distributed against the cutting end of the bit'withoutleakage or wear about the upper end of the blade. 7 I. i j

I contemplate the provision in the head of the bit of a packing means about the joint between the head and the blade whereby a tight seal may be easily formed which will" prevent the loss of flushing fluid around the" joint and consequent wear at that point It is a further obj e'ct to-so form the blade and the socket in the head int-0 which the blade is fitted, that a firm and rigid connection may be formed betweenthe blade and the head so as to avoid any relatlve movement in use. 1

The invention resides in the particular construction and arrangement of the parts 7 making up the bit, a full disclosure of which will be made in the specification which follows:

With reference to the drawings herewith,- Fig. 1 is a front view partly in central vertical section illustrating one form ofmy' in-;

mately on the plane 44: of Fig. 1 and illus-f trating a slightly different formof through bolt employed in securing the parts to- 5 gether.

Fig. 6 is a top plan view of blade removed from the bit head.

ENT oFFic a four-way F ig. 7 is a front elevation of the blade shown in Fig. 6.

Fig. 8 is a side elevation of the blade shown in Fig! 7, the broken lower the bit head being shown in section.

.end of Fig. 9 is abroken, vertical section of the connecting device shown in Fi'g. 5. r

In forming my bit I employ a bit head 1 having, a tapered upper shank 2 t for engagement with the drill collar,

hreaded or cou-' pling. The head 1 is approximately. cy-' lindrical in .shape at its upper end,

and the body portion?) of the bit head is widened out in theplane of the blade of the bit and is approximately. oval in cross section, as

shown in Fig. 3 The lower end of t is rounded somewhat andprovided transverse slot therein to receive the bladeof w he body with a the'bit. This slot is formed centrally with a socket 4 which is tapered upwardly into the head and terminates in a shoulder '5 against which a packing ring, or gasket .6

of compressible packing may be placed.- h

through There'is a longitudinal passage 7 the head of the bit terminating in th 4. As will be seenin Fig. 1, the 's 'sive, a so-called two-way blade is i This blade is. formed like the usual fishlower end, having cutting tail bit at its e socket p lot 8 at each side of the socket is also tapered upwardly to receive the blade 9 of the bit.

The blade 9 may be a so-called two-way or four-Way blade. In Figs. 1 to i, inclushown.

edges 10: at the lower end, the blade being divided midway of {sides and curved forwardly in the direction ofrotationof the b1t, one edge being curved in a direction.

opposite to that of the other.

Midway of thesides of the'blade and spaced upwardly from the lower. end is a head rounded at 12 adjacent the lower end and is tapered upwardly to fit within the socket against the. packing ring 6. .The socket/1 1 formed in thehead ll-oi corresponding with the size of the through the body of the bit head.

" 4 in the head of the bit. At its upper end itis provided with a shoulder 13 to abut re is a the bit passage 11 which i This passage, of recess in the head terminates short of the lower end 12 on the blade, and is provided with outwardly inclined fiuid passages 15, one on each side of the head, discharging on to the forward face of the cutting blade.

I provide a removable water pipe 16, through the head of the bit and projecting somewhat into the head of the blade 9. It

overlaps the packing gasket 6 andforms a seal therewith when the blade is drawn firmly into the head. understood from Fig. 1. While this water pipe ltiis made removable it is to be understood that it may be formed integrally with the head if desired.

The blade is secured within the body of the bit by through bolts 17, one on each Side of the body and extending through the slotted openings 18. in the blade. These through bolts 'may be of ordinary character having a-nut 19 on one end thereof whereby the bolt may be tightened rigidly.

While I have shown an ordinary through bolt employed for this purpose, I also contemplate a through bolt such as is. shown in Figs. 5 and 9. In this arrangement I use a key or bushing 20 which may engage through a tapered opening 18 in the body and the blade. The said opening 18, as shown in Fig. 9, is elongated So'that when the key or bushing 20 is engaged therein it will have a wedging contact with the upper wall of the slotted opening 18, and as the key is drawn into position by'a bolt or screw 21, the blade will be forced upwardly into the tapered slot 8 in the head. 1

In Fig. 5 I have shown the key as being formedwith a threaded socket to receive the cap screw 21, and it will be noted that when the said screw is tightened into the socket in the key, the key will be drawn tightly into position. In Fig. 9, an ordinary slotted screw head is formcdon the bolt so. that a screw-driver may be employed in tightening the key.

In Figs. 6, 7, and 8 I have shown a socalled four-way bit. Theblade 9 is similar in general shape to that shown in the first embodiment. However, in this modification,

the blade 9 is approximatelyshorter and extends but a short distance below the lower curved end 12 of the head of the blade. There is also formed a second blade 23 at right angles to the blade 9 and terminating at 2d shortly above the lower end of the blade 9. Said blade 23 projects forwardly beyond the blade 9 and has the usual cut. ting edge 25 commonly used on fishtail bits.

The channelsv for the flushing fluid are.

formed at 26 and 27 to discharge the fluid toward the cutting edges or" the bladesv 9- and 23. It is to be understood that, the tourway blade is secured in the body-of the bit This construction will be in the same way as was noted relative to the first described blade.

It will be noted that when the blade is assembled in the body of the bit, as shown in Figs. 1 and 2, the assembled device will be of general oval shape except for the lower cut-ting edge which is adapted to be washed eilectivelyby the flushing fluid. This shape of the head and blade allows the device .to be easily cleared of material tending to adhere thereto and this bit will hence be difficult to ball up with mud, as is usually the case with fish t-ailbits. Furthermore, if it is necessary to spud with this bit, any material thereon may be easily loosened. Furthermore,-this structure is easy to assemble,in that the blade of the bit may be easily fitted within the lower end or" the head and then tightened into position by means of the through bolts. hen thus tightened, the up per end otthe blade;engages firmly with the packing gasket '6 so that no leakage can occur out ofthe channel 7 for the flushing fiuid. Thisavoids any tendency for wear at this point, and materially lengthens the life of the tool. Due, also, to the shape of the blade, and the socket in which it engages", a

tight wedging fit is obtained which avoids loosening ofthe blade in the body of the bit. However, if the blade tends to become loos ened, it may be easily tightened by means of the bolts or screws 21.

The further advantages of this tool'will be obvious to those skilledin the art.

Having described my invention, what I 1 claim is:'

l. A bitjof the character described com-' prisinga, bit body, .adetachable blade having its upper end tapered, a head axially of said blade tapered upwardly toa shoulder, 1 a socket in said body to receive said head, slots oneach side of said socket shaped to form a wedging fitwith said blade, said head and bit body being constructed with registering openings forming a passage for 1 flushing fluid axially thereof, said head having channels leading to the lower cuttingedgeof said blade, and means to form a said body der, a socket in-said body to receive saiid120 head, slots on each side'of said socket shaped totorm a wedging fit with said blade, Said head and bit body being constructed with: registering openings forming a passage for flushing fluid axially thereof,- saidhead hay ing channels leading to the lower cutting edge of said blade, a removable pipe .in said bodyoverlapping said shoulder and packing means in-saidbody adapted to be engagedby said shoulder. J 1

' prising a body approximately oval in transverse cross section, a tapered threaded shank thereon, an upwardl tapered slotted recess in the lower end-o said head, a fish tail blade fitting in said recess, the upper end of said blade being tapered in thickness and beveled upward from its side edges, means to wedge said blade firmly into said tapered recess, and secure it therein, a fluid channel in said body and said blade, and means to form a seal about said channel at the upper end of said blade.

5. A drill bit having a body, a tapered shank thereon, an upwardly tapered central socket in the lower end of said body, slots communicating with said socket, a blade having a head tapered to fit within said socket, a channel for flushing fluid axially through said body and said head to a point short of the lower end of saidhead, outlets from said channel, means on said body extending into the channel in said blade, means to seal about said channel at the upper end of said blade, and means to secure said blade in said body.

' 6. A drill bit having a body, a tapered shank thereon, an upwardly tapered central socket in the lower end of said body, slots communicating with said socket, a blade having a head tapered to fit within said socket, a channel for flushingv fluid axially through said body and said head to a point short of the lower end of said head, outlets from said channel, longitudinally extending slotted openings in said blade, keys fitting transverselythrough said head and through said openings, and screws to tighten said keys and draw said blade firmly into said body.

HERBERT J. HAWTHORNE. 

